Device for layered stacking a support

ABSTRACT

A device for automatically stacking packages on a support comprising at least one feeding conveyor; a lifting and lowering unit for lifting and lowering a pallet; a position conveyor embodied as a travel container, which is arranged horizontally and longitudinally to one side of the storage place, in order to position the packages in the X-direction; at least one sliding plate and a pusher in order to transport the packages from the travel path in the Z-direction to the predetermined position in the stack. The at least one sliding plate may comprise a flat, strip-like plate that can move horizontally and longitudinally on the side of the storage place and transversally thereto, in order to remove packages from the positioning conveyor in the X direction when pushed by the pusher and arranging on the pallet in the Z-direction. The travel container contains pivotable stops and can be moved on rails.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims the priority benefits of InternationalPatent Application No. PCT/EP2013/063343, filed on Jun. 26, 2013, andclaims benefit of DE 10 2012 106 111.4, filed on Jul. 6, 2012.

BACKGROUND OF THE INVENTION

The invention relates to a device for automatically stacking packages ona support in a predetermined spatial arrangement to form a stack.

Automatic stacking of a support or a carrier, in particular a pallet ora trolley, with packages to form a stack for subsequent shipment, i.e.“palletizing” is known per se. However, in that case packages of uniformsize or dimension are placed by robots, grabbers etc. intoarithmetically determined locations.

In contrast, the process of automatically loading a load carrier withpackages of different characteristics to form a stack is the so-calledautomatic “mixed-case” palletizing.

Current distribution logistics place ever increasing demands uponpicking. Therefore, it is necessary to develop picking systems whichprocess orders automatically without manual intervention.

Thousands of different products (or packages) of the most variedcharacteristics (size, shape, weight, dimensions, surfaces etc.) must bepicked automatically in such systems.

In that case, it is necessary to take into account various aspects whichenormously increase the complexity in comparison with “simple” manualstacking of simple, regular geometries. For instance, a subsequentpackage can only be stacked or placed effectively onto a precedingpackage if the latter comprises a flat or planar surface which shouldalso be oriented approximately in a horizontal manner, and if thepackage can support the weight of the further packages, which are placedthereon, without being damaged.

Furthermore, the stack which is formed should comprise a certain levelof stability, inter alia to ensure that it does not fall over duringtransportation. Although a film wrapping helps, it cannot stabilize anincorrectly formed stack on its own.

Furthermore, customers demand with increasing frequency that the stacksare optimized by reason of the desired unloading sequence.

Therefore, different packages or goods of a different size or dimensionare generally still stacked manually, as the requirements placed on thestability of the stack, the packing density within the stack and thesequence of loading and the resulting unloading sequence and not leastthe stacking capability of the goods are extremely high and to date havenot been fulfilled or have only been partly fulfilled by the knownmethods and devices.

EP 1 462 394 B1 discloses a device for automatically loading a loadcarrier with packing units which form a stack, i.e. a device forpalletizing. In the case of the device, the packing units are fed lyingsupported and individually on trays from where they are placed onto apacking table. At this location, the packing unit, lying on the table,is displaced by a pusher along the broad side of the pallet to be loadeduntil the loading coordinates in the X-direction are reached.Subsequently, a further pusher and a loading tongue simultaneously pushthe packing unit in the direction of the load depth over the palletuntil the loading coordinates in the Z-direction are reached.Subsequently, the loading tongue moves back, wherein the pusher remainsstationary and serves as a scraper, so that the packing unit is placed“free-falling” at the desired position on the pallet. The stack whichforms is supported by a loading aid on the remaining three sides.Stacking thus occurs as it were “against the wall”. However, thedisplacement on the packing table is time consuming and owing to therestricted accessibility has disadvantages when forming the packingpatterns. Moreover, it is vital that the loading tongue and thescraper/pusher move simultaneously in the X-direction. Also, only onepacking unit can ever be “processed” sequentially.

WO 2010/059923 A1 discloses an automatic robot-assisted device forstacking, in which an intermediate plate is used for forming the firsttier of a stack and simultaneously changing the pallet.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a method and a devicefor automatically stacking packages onto a carrier in a predeterminedspatial arrangement to form a stack, which method or device permits in aflexible manner mixed-case stacking at a high throughput rate.

Advantageous embodiments are apparent from the claims and thedescription.

In accordance with an aspect of the invention, the positioning conveyoris designed as a transfer cart or shuttle which can travel back andforth on rails arranged in the X-direction along the stacking locationor the support for it and transports in each case one package to thedesignated X-position.

Preferably, the transfer cart is designed having a C-shaped frame, sothat the at least one sliding plate can engage through between the limbsof the “C”, so as to prevent any mutual hindrance. This also renders itpossible that once the “transfer” of the package to the sliding platehas been effected, the transfer cart already travels back to receive thenext package from the feeding conveyor before the stacking procedure iscompleted. The actual carrier surface for the package is thus fastenedonly on one side to the travelling mechanism of the transfer cart andprotrudes at this location.

In order to ensure that the packages do not fall down from the transfercart and are precisely positioned, the transfer cart comprises a stop onthe side facing away from the feeding conveyor in the X-direction. In aparticular embodiment, the stop is movable, preferably foldable orpivotable, away from the stop position, so that after “transfer” of thepackage to the sliding plate has been effected (cf. above), the transfercart is already able to “fetch” the next package.

For instance, the stop is designed to be movable away from the stopposition. For this purpose, the stop can preferably be pivoted about anaxis from the stop position to a release position. This embodiment doesnot require much space and also does not “collide” with the slidingplates. It is expedient if the stop comprises two stop wings which arepivotable in opposite directions, in order to provide a broad stop orsurface.

If, as in the case of the prior art, an individual pusher is not usedbut instead the pusher is designed as an arrangement of a plurality ofindividual pushers arranged horizontally and along the side of thestacking location, i.e. designed as a bank of pushers, which effectpushing of the packages from the positioning conveyor in the directionof the stack, wherein the individual pushers are movable in theZ-direction independently of the at least one sliding plate, in order toretain the package when the sliding plate is being retracted, thepackages can still be positioned in a more variable manner and moreovera plurality of packages can be stacked with less of a time offset oreven simultaneously.

In a particular variant, not all of the individual pushers comprise adedicated drive but instead have at least one, preferably two, commondrives which can be coupled optionally to a specific individual pusherto drive same. For this purpose, the drive can be movable and can enterinto engagement with a drive carriage of the respective (adjacent)pusher(s) via a coupling element.

The individual pushers are thus suspended from a frame, on which theyare movable in the Z-direction towards (or away from) the stack. Forthis purpose, they are approached by a carriage or cross member which isarranged above and extends transversely thereto, i.e. in theX-direction, and supports a drive, wherein a coupling or entrainingelement establishes the operative connection between the drive and theindividual pusher. The entraining element is suspended in the manner ofa sheet or strip from the drive or the travelling cross member thereofand engages into a groove, which is open at the top, on the drivecarriage of the adjacent individual pusher(s), for which reason theentraining element is of a corresponding width.

Preferably, two such movable common drives are provided, one coming fromeach side in the X-direction of the frame and one positioned upstreamand downstream in the X-direction with respect to the stacking location.

The arrangement of the individual pushers can extend over the entirelength of the positioning conveyor, then the individual pushers can bedesigned to be unmovable in the X-direction or conveying direction ofthe positioning conveyor. Alternatively, it is also feasible to providecorrespondingly fewer individual pushers, but at least two, and then todesign same to be adjustable in the X-direction for balancing purposes.

In a preferred embodiment, the at least one sliding plate is designed asa flat, strip-like plate which is designed to be movable horizontallyand along the side of the stacking location and transversely thereto andwhich becomes thinner in the direction of the stacking location. Thesliding plate is suspended on the side of the positioning conveyoropposite the carrier. At this location, it is optionally attached to thesame frame as the individual pushers. If more than one sliding plate ispresent, they can be arranged in parallel and next to one another.

It is preferred if the at least one sliding plate is movable back andforth in the manner of a carriage in each case on a linear axle orientedin the Z-direction. Therefore, it can be extended or retracted in simplemanner into the required Z-direction towards the stack and is stillrigid enough by reason of the long bearing surface or number of bearingpoints. The drive can be effected e.g. by means of a toothed belt,toothed rack etc.

It is understood that depending upon the design of the positioningconveyor the sliding plate engages underneath or through the positioningconveyor, in order to position a package on the other side in the stack.

It is also possible to design the at least one sliding plate to bemovable in the longitudinal direction (X-direction) of the positioningconveyor, in particular if only one or a few, preferably two, slidingplates are provided. Then, they can be movable jointly or independentlyof one another. If they are movable independently of one another, aplurality of packages can be displaced simultaneously onto the carrieror into the stack.

Alternatively, in accordance with the number of individual pushers, itis also possible to distribute a corresponding number of sliding platesuniformly over the length of the positioning conveyor. Then,adjustability in the X-direction is not required. Each sliding plate isthen preferably “allocated” to an individual pusher and is arranged withthe individual pusher in a vertical plane, i.e. arranged flush one ontop of the other as seen from above. The sliding plates can likewise bedesigned with common drives in a similar manner to the individualpushers (see above).

It is likewise possible to control selected individual pushers jointly,so that e.g. two to four adjacent individual pushers move one relativelylarge package together at the same time. Accordingly, the sliding platescan also be controlled jointly.

In order to provide a structurally simple and non-obstructivesuspension, it is expedient if the arrangement of the individual pushersis fastened to a frame extending above the positioning conveyor. Theframe rests preferably on rail-like profiles and also serves as asupport or suspension for the sliding plates. Therefore, the frame,together with the arrangement of the individual pushers and the slidingplates, forms a modular pusher/sliding plate unit.

In the case of highly complex automatic systems and procedures such asthis, all manner of planning cannot prevent the occurrence ofmalfunctions, e.g. because a package falls over during stacking. Then,an operator is required to intervene manually. In one embodiment, inorder to permit or facilitate the intervention of an operator, it isthus provided that the frame, together with the unit consisting of thepusher and sliding plates, is movable away from the stacking location,which can be effected manually or in a driven manner. For this purpose,the unit is preferably displaceable in the manner of a rail, inparticular by means of a drive. Preferably, the drive is a spindle whichis driven manually or by motor. It is likewise expedient if thepositioning conveyor is fastened to the frame, so that the positioningconveyor is likewise “removable”. This option of manually overcoming amalfunction or of manually loading increases the availability of thedevice.

A shifter for the packages can be arranged between the feeding conveyorand the positioning conveyor. It can be designed as a pusher. It ispossible for the pusher, together with the transfer cart, to transportthe package to the desired X-position, so that the package istransported virtually “clamped” between the pusher and lateral stop ofthe transfer cart. Therefore, high accelerations and speeds can beachieved during positioning without the risk of packages beingdisplaced, falling down etc.

Therefore, in one variant the pusher (shifter) is movably suspended anddriven on a rail which extends along the carrier and runs in parallelwith the positioning conveyor.

However, it is also feasible for the feeding conveyor to place thepackages directly onto the positioning conveyor without theinterposition of a shifter. In one variant, the feeding conveyorterminates for this purpose perpendicularly with respect to thepositioning conveyor and “pushes” the packages directly onto thepositioning conveyor.

Overall, it is possible in this way to effect stacking of the carrier ina flexible manner and with a high level of efficiency. In particular, abroad spectrum of different packages can be stacked continuously. Forinstance, in addition to the uniform packages which are not very awkwardand can likewise be handled as a matter of course, packages having themost varied dimensions can be stacked consecutively onto the carrier.

The packages can be the most varied goods, such as packaged goods, goodspackaged in groups, such as cardboard boxes, crates, containers, goodson trays, packing units, such as film-wrapped multipacks of plasticbottles etc., as well as individual articles of any type.

The support can be intermediate plates or carriers, such as pallets andtrolleys, or similar supports for piece goods and the packaging thereof.

A feeding conveyor is understood to be conveyors in general and inparticular roller conveyors, conveyor belts and conveyor systems. Theycan be loaded manually or automatically. The packages are singulated anddelivered in the correct sequence for the desired packing sequence onthe conveyor equipment. The correct sequence is determinedarithmetically as an order is being processed. Corresponding softwarefor this purpose is known. The special feature resides in the fact thatthe packages are delivered on the feeding conveyor without any auxiliarymeans, such as trays, containers etc.

The packages are thus delivered in singulated fashion. However, it isalso possible to arrange groups of identical or very similar packed orunpacked items for collective handling. This grouping is then effectedeither in the region where the packages are received from the feedingconveyor by the displacement means or even when the feeding conveyor isbeing loaded. The particular design of the pusher as a bank makes itpossible specifically for packages such as these to be transferred orpositioned together.

It is also favorable if the packages are oriented before being receivedby the displacement means. This allows the packages to be received bythe displacement means in standardized and thus simplified manner.Alternatively or in addition, corresponding optical methods fordetecting the orientation of the packages and controlling thedisplacement means can also be used, in order to achieve the orientationtherewith. The orientation can be effected e.g. by means of the shifter.The movable stop can also be used for orienting purposes.

It is expedient if the stack on the carrier is stabilized during and/orafter stacking. Therefore, the individual layers maintain theirstructure and the stacked carrier can be transported more securely.

In order to stabilize the stack after stacking (complete stack orindividual layers), the stack can be stabilized together with thestacked carrier by having a film, net or the like wrapped around it.Wrapping can be performed in layers gradually during stacking or afterstacking of one layer. In this case, stabilization takes place withinthe actual stacking device. The already partially stacked carrier islowered by the depth of a layer in order to adapt the level for stackingpurposes. This is utilized because already formed layers of the stackcan “slide downwards” and be wrapped in layers below the stacking level,while “at the top” stacking continues. This saves time. For thispurpose, a film wrapping device is integrated directly into the device.This has the advantage that the carrier with a formed stack does nothave to be moved separately. For instance, stabilization can be effectedeach time a tier or layer has been lowered. As a result, it is possibleto achieve a high level of stability in the stack even when the carriershave not actually been stacked in a completely stable manner. This alsogreatly expands stack-forming options in terms of the goods andselectable sequence.

Of course, as an alternative to the film-wrapping technique all otherknown stabilization options can be used. This includes e.g.shrink-wraps, nets and other stretchable materials as well ashook-and-loop fasteners and adhesive connection means etc.

During actual stacking, stabilization can be effected by means oflateral walls arranged in a U-shaped manner around the stacking locationor carrier, so that stacking can be performed “against the wall”. Thesidewalls and the rear sidewall can be adjusted or moved verticallyand/or horizontally in relation to the stacking location. Therefore,carriers etc. of a different size can be loaded and the walls can serveas a scraper in conjunction with intermediate plates.

Depending upon the packages to be stacked, it may be necessary for thepurpose of protecting the packages or for increasing the stackingcapability etc. to place inserts, e.g. consisting of cardboard orpaperboard, between, below or above the layers. For this purpose, theflat material can be appropriately stocked and/or delivered and can beplaced by means of suckers provided on the handling means.

The carriers (e.g. pallets) and also the inserts (cardboard) can bedelivered and presented by means of separate conveying equipment. Thecarriers or inserts can be received or transferred using dedicatedequipment.

In one embodiment, it is arranged that an intermediate plate is providedat the level of the positioning conveyor above the carrier to be loaded.The intermediate plate provides a uniform smooth surface for forming astack and permits further stacking in spite of any change of carrier.

The intermediate plate is divided preferably in the middle and each partis designed to be displaceable towards the side.

In one variant, the first tier of a stack is formed on the intermediateplate, while the completely loaded carrier from the preceding stackingprocedure underneath it is swapped for a new empty carrier. Therefore,the stacking procedure can be continued without interruption. If thefirst layer is formed and the new carrier is present, the parts aremoved to the side and the first layer is transferred in this manner ontothe underlying carrier, on which stacking subsequently continues.

In a preferred alternative, the complete stacking procedure takes placeon the intermediate plate which for this purpose is designed to beheight-adjustable. This has the advantage that the transfer to thecarrier only takes place after stacking and the carrier does not have tobe “swapped”. As a result, the total throughput rate of the device isincreased. Moreover, the optionally provided stretch film-wrapping canbe effected more easily.

When the intermediate plate is moved apart or opened, the lateralstabilization walls serve as a scraper, i.e. the intermediate platemoves laterally below the lower edges of the walls.

There is a greater requirement for the stacked packages to be providedin so-called trolleys or rolling containers. They can be loaded easilyinto trucks and unloaded in situ and moved, as they comprise rollers.Moreover, they comprise sidewalls which permit stable stacking andeffective stabilization by means of stretch film, so that transportationis likewise secure. However, these characteristics cause problems duringautomatic stacking.

In accordance with the invention, it has been recognized that automaticstacking is possible in a reliable manner if the sidewalls of thetrolley are held by a spreading device at least perpendicularly or evenbent open in a slightly inclined manner outwards. The sidewallsspecifically have the characteristic of moving inwardly towards oneanother.

It has also been found that stacking of trolleys can be facilitated iffor this purpose a separate and optionally height-adjustableintermediate plate is provided which is arranged on the side of thestacking location or the carrier remote from the positioning conveyor orcan be introduced from this side into the trolley.

Therefore, the device in accordance with the invention can be used forstacking pallets etc. or trolleys alternately according to requirement.

The rear sidewall can serve as a scraper when the completely stackedstack is transferred to the trolley by retracting the furtherintermediate plate. In one embodiment, the rear sidewall is alsoheight-adjustable and/or movable in the direction of the positioningconveyor, so that trolleys of a different size can be used.

This preferably also serves as an attachment location for the spreadingdevice.

The spreading device consists preferably of two pins which are arrangedat the same height in the region of the expected sidewalls of thetrolley, protrude from the sidewall forwardly into the trolley space andcan be displaced laterally outwards for spreading purposes. For thispurpose, the pins are preferably arranged in each case on a verticallyoriented rotary disk in the rear sidewall.

For ease of transportation and handling within the system, the trolleysare moved on transport pallets which can be handled in the same manneras normal pallets.

Further details of the invention will be apparent from the descriptionhereinafter of exemplified embodiments with reference to the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic perspective view from one side of a device forthe automatic layered stacking of pallets;

FIG. 2 shows a schematic perspective view of the device of FIG. 1 from adifferent angle of view;

FIG. 3 shows a schematic perspective view of the displacement means ofthe device of FIG. 1 as a package is received;

FIG. 4 shows a schematic perspective view of the displacement means ofthe device of FIG. 1 as the package is transported in the X-direction;

FIG. 5 shows a schematic perspective view of the displacement means ofthe device of FIG. 1 as transportation of the package in the Z-directioncommences;

FIG. 6 shows a schematic perspective view of the displacement means ofthe device of FIG. 1 as transportation of the package in the Z-directioncommences, from a different angle of view;

FIG. 7 shows a schematic perspective view of the displacement means ofthe device of FIG. 1 during further transportation of the package in theZ-direction;

FIG. 8 shows a schematic perspective view of the displacement means ofthe device of FIG. 1 as transportation of the package in the Z-directionends;

FIG. 9 shows a schematic perspective view of the displacement means ofthe device of FIG. 1 after transportation of the package in theZ-direction has ended;

FIG. 10 shows an enlarged detailed view of the common drive of theindividual pushers;

FIG. 11 shows an enlarged detailed view of the transfer cart;

FIG. 12 shows a schematic perspective and enlarged view of the device ofFIG. 1 in the region of the stacking location as the stacking procedureends;

FIG. 13 shows a schematic perspective and enlarged view of the device ofFIG. 1 in the region of the stacking location as the stack istransferred from the intermediate plate onto a pallet;

FIG. 14 shows a schematic perspective and enlarged view of the device ofFIG. 1 in the region of the stacking location as the stack is lowered;

FIG. 15 shows a schematic perspective and enlarged view of the device ofFIG. 1 in the region of the stacking location as the stack is wrapped infilm and transported away;

FIG. 16 shows a schematic perspective view of the device duringautomatic layered stacking of the trolley in the region of the stackinglocation during stacking;

FIG. 17 shows a schematic perspective view of the device of FIG. 16 at adifferent angle of view, wherein the rear stabilisation wall is omittedfor improved clarity;

FIG. 18 shows an enlarged view of the device of FIG. 16 during spreadingof the trolley sidewalls, and

FIG. 19 shows a detailed view of the mechanism for spreading the trolleysidewalls.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1 to 19 show a device, which is designated as a whole by thereference numeral 1, for automatic layered stacking of pallets P withpackages W of different dimensions in a predetermined spatialarrangement. This is a device for “mixed-case” palletizing. Naturally,the device 1 can also be used for palletizing merely similar packages W.

The device 1 comprises a roller conveyor 2 as a feeding conveyor whichprovides the singulated packages W in a computer-aided predeterminedsequence from a warehouse, not shown.

Arranged at the end of the roller conveyor 2 is a shifter 31 which isdesigned as a pusher 3 and shifts the packages W by 90® and places themonto the subsequent positioning conveyor. The packages W are likewiseangularly oriented, so that they are oriented on the positioningconveyor 4 insofar as their outer shape allows.

The positioning conveyor 4 is designed as a transfer cart. It serves toposition the packages W in the X-direction, in order to adopt thiscoordinate of the subsequent position in the stack.

The positioning conveyor or the transfer cart or more precisely thetransport surface 35 thereof is arranged horizontally at the same leveland along a side of the location 6 for stack formation. The carrier P(pallet) or trolley (R) which is to be loaded will typically be locatedhere.

At the level of the transport surface above the carrier P to be loaded,an intermediate plate 8 is provided in the location 6. The intermediateplate 8 is divided in the middle and each part 8A, B is designed to bedisplaceable towards the side (in the X-direction) such that a stack isformed on the intermediate plate 8, whereas the completely loadedcarrier P from the preceding stacking procedure underneath it is swappedfor a new empty carrier P. Therefore, the stacking procedure can becontinued without interruption.

In order to feed empty pallets or remove stacked pallets, acorresponding roller conveyor 9 is provided below the stacking location6.

The respective pallet P is received from the roller conveyor by alifting and lowering unit 10 for lifting and lowering the carrier P inthe Y-direction and is moved upwards to the stacking location 6. Thelifting and lowering unit 10 is also responsible per se for adapting thelevel during stacking, i.e. it performs a lifting or a lowering movementas necessary during stacking of a package W and also performs adaptationof layer balancing at the beginning of a new layer.

The respective package W is thus pushed in the Z-direction by thetransfer cart 4 onto the desired position in the stack laterally intothe location 6 onto the intermediate plate 8.

For the purpose of this displacement of the packages W to thepredetermined position in the stack S, the device comprises slidingplates 11 and a pusher bank 12, i.e. in each case a plurality ofindividual sliding plates 13 and individual pushers 14 arranged next toone another horizontally and along the side of the stacking location 6or the pallet P.

The sliding plates 13 engage through between the frame of the transfercart 4 and receive the package W pushed by the pusher 14. Subsequently,the pusher and the sliding plate travel together to the desired positionand the sliding plate 13 is retracted, whereas the pusher 14 remainsstationary to retain the package W. Therefore, the package W ispositioned. The sliding plates 13 become flat at the front, so thatpositioning can be effected as precisely as possible.

The sliding plates 13 are each designed as flat, strip-like plates whichare movable horizontally and along the side of the stacking location 6and transversely thereto and which become thinner in the direction ofthe stacking location 6.

The sliding plates 13 are suspended on the side of the transfer cart 4opposite the carrier and are arranged in parallel and next to oneanother. They are each movable back and forth in the manner of acarriage on a linear axle 16 oriented in the Z-direction. The drive iseffected for each axle by means of an electric motor 16E and a toothedbelt (not shown) which is arranged on the linear axle and into which thecarriage or the sliding plate 13 is hooked.

Therefore, the sliding plates 13 form as it were an optional widening ofthe transfer cart 4 into the stacking location 6.

The pushers 14 are arranged flush with one another horizontally andalong the side of the stacking location 6 or the carrier P and aredesigned to be movable independently of one another. They are arrangedon the side of the positioning conveyor opposite the carrier or are inthe rest position at this location, in order to extend over the transfercart 4 for the purpose of pushing packages.

The pushers, like the sliding plates, are also arranged over the entirelength of the stacking location 6 or the pallet P and are fastened to aframe 17 mounted above the positioning conveyor. At this location, theyare each movable back and forth in the manner of a carriage on a linearaxle 18 oriented in the Z-direction. The drive is effected for each axleby means of an electric motor 18E and a toothed belt (not shown) whichis arranged on the linear axle and into which the carriage or thepushers 14 is/are hooked.

The pushers 14 extend from the respective linear axle downwards to aheight only just above the surface of the transfer cart 4 and compriseat the end at that location a flatly enlarged base for handling thepackages W more effectively and more safely.

Provided below the stacking location 6 is a unit 19 for wrapping theformed stack S in a film.

Wrapping is effected in layers gradually during stacking or afterstacking of a layer. The carrier P comprising the already formed layersof the stack S is lowered gradually downwards by the lifting andlowering unit 10 and thus travels through the annularly formed unit 19in order to be wrapped.

If the entire stack S is completed, the stack S is transferred to thepallet P and is moved downwards and transported away via the rollerconveyor 9.

At the same time, the intermediate plate 8 is closed and stackingcontinues thereon to form the next stack of the next order.

Overall, in order to automatically stack packages W onto a pallet P in apredetermined spatial arrangement to form a stack S, the sequence andspatial position of the packages W on the pallet P are determined in acomputer-aided manner in order to create a stack S using the orderforming the basis thereof.

The packages W are then acquired individually without auxiliary means(trays etc.) from a warehouse etc. in a predetermined sequence, which isrequired for this purpose, by means of the feeding conveyor 2. Thepackages W to be loaded are then shifted from the feeding conveyor 2 bythe shifter 3 onto the transfer cart 4.

By means of this and the pusher bank 12 and sliding plates 13, therespective package W is transported to the predetermined spatialposition on the pallet P or the stacking location 6 or intermediateplate 8 in the stack being formed.

Depending upon requirement, the pallet P is lowered or raised in theY-direction by the corresponding unit 10.

It is apparent from FIG. 10 that the individual pushers of the pusherbank do not each comprise dedicated drives.

The individual pushers comprise two common drives 21, 22 which can beoptionally coupled to a specific individual pusher in order to drivesame. For this purpose, the drives 21, 22 are movable in the X-directionon the frame 17 above the individual pushers by means of a cross member21T, 22T and can be coupled to the drive carriage 23 of the individualpushers 14.

The drive 21, 22 comprises in each case an actual drive block 24, 25which is movable in the Z-direction in a similar manner to the aboveembodiment of the pushers. In order to drive the respective individualpusher 14, the drive block 24, 25 comprises a coupling lug 26 whichpoints in the direction of the drive carriages 23 and engages into agroove 27, which extends transversely with respect to the X-direction,in the drive carriage 23.

In order to drive a specific individual pusher, the drive 21 or 22,depending upon the individual pusher, is moved by means of the crossmember in such a manner that the corresponding coupling lug 26 engagesinto the groove 27 of the respective drive carriage 23. Subsequently,the drive block 24 or 25 is moved and entrains the drive carriage 23 orthe individual pusher 14 in the Z-direction.

The individual pushers are thus suspended from a frame, on which theyare movable in the Z-direction towards (or away from) the stack. Forthis purpose, they are approached by a carriage or cross member which isarranged above and extends transversely thereto, i.e. in the X-directionand supports the drive, wherein a coupling or entraining elementestablishes the operative connection between the drive and theindividual pusher.

It is also apparent that the entraining element (coupling lug 26) issuspended in the manner of a sheet or strip from the drive or its travelcross member 21T, 22T and engages into a groove 27, which is open at thetop, on the drive carriage of the adjacent individual pusher(s) 14, forwhich reason the entraining element 26 is of a corresponding width, sothat it can engage by means of corresponding positioning either into thegroove 27 of an individual pusher or into the two grooves 27 of adjacentindividual pushers 14.

Only two sliding plates 13 are used which are then movable in theX-direction along the stacking location 6 by means of a drive 28, 29, sothat the respective sliding plate can be positioned corresponding to anindividual pusher. For this purpose, the respective linear axle of thesliding plate is designed to be movable in a similar manner to a crossmember. An arrangement corresponding to the individual pusher bankwithout movement of the sliding plates in the X-direction would also befeasible.

It is also possible to control both sliding plates together, so that apackage W is supported on both sliding plates at the same time.Obviously, this can be combined with a corresponding control and use ofe.g. two individual pushers.

The transfer cart 4 receives individual packages W from the feedingconveyor 2. For this purpose, the shifter 31 pushes the packages fromthe feeding conveyor 2 onto the transfer cart 4.

The transfer cart 4 comprises a movable stop 32 on the remote side, inorder to prevent the packages W from falling off the actual transportsurface 35 and to permit precise positioning. In order to ensure thatthe package W does not fall off when the transfer cart 4 is accelerated,the shifter 31 is moved in synchronism with the transfer cart 4 in theX-direction, so that the respective package is transported on thetransfer cart 4 clamped between the stop 32 and the shifter 31.

For movement in the X-direction, rails 33 are provided, on which thetransfer cart 4 is movable between the stacking location 6 and thepusher/sliding plate unit. Arranged above and in parallel therewith is acorresponding rail 34 for the synchronous movement of the shifter 31.The rails 33, 34 are similarly fastened to the frame 17.

The transfer cart 4 is designed having a C-shaped frame 36, so that theat least one sliding plate can then engage through between the limbs ofthe “C”, so as to prevent any mutual hindrance.

The actual carrier surface 35 for the package is thus fastened only onone side to the travelling mechanism of the transfer cart 4 andprotrudes at this location.

The stop 32 is movable, preferably foldable or pivotable, away from thestop position, so that after “transfer” of the package to the slidingplate has been effected (cf. above), the transfer cart is already ableto “fetch” the next package.

For this purpose, the stop 32 can preferably be pivoted about an axisfrom the stop position to a release position. This embodiment does notrequire much space and also does not “collide” with the sliding plates.The stop comprises two stop wings which are pivotable in oppositedirections, in order to provide a broad stop or surface.

This also renders it possible that once the “transfer” of the package Wto the sliding plate has been effected, the transfer cart alreadytravels back to receive the next package from the feeding conveyor 2before the stacking procedure is completed.

The transfer cart 4 thus travels with the package W, which is clamped bythe folded-up stop 32 and shifter 31, to the respective pre-calculatedX-position on the rails 33.

At the same time, the cross members 21T, 22T for the individual pusherstravel from the left and right in the X-direction to the requiredposition in order to interact with the drive carriages 27 of theindividual pushers 14, wherein the entraining element 26 engages intothe respective groove 27. The sliding plates 13 are likewise positionedin the X-direction.

Then, as described, pushing from the transfer cart 4 (positioningconveyor) is effected by the individual pushers, two pushers in thiscase, onto the sliding plates, also two in this case, for which reasonthe drive block 24, 25 travels along the cross member in the Z-directionand in this way entrains the individual pusher 14 in each case.Accordingly, the two sliding plates 13 are extended in the Z-direction,in order to receive the package W from the transfer cart 4, wherein theycan “engage through” the transfer cart 4 by reason of the C-shaped frame36.

As soon as the package W rests completely on the sliding plates, thestop 32 is folded down and the transfer cart 4 can travel back for thepurpose of receiving.

The stop 32 is formed by means of two stop disks 37A, B which arerotatable anticlockwise and clockwise respectively. The stop disk 37A ispivoted or folded down in an anticlockwise direction and the stop disk37B is pivoted or folded down in a clockwise direction from the uprightposition bounding the package W, so that the transfer cart 4 is free.

Also illustrated is a manually operated crank K which drives themechanism in order to permit or facilitate manual intervention, forwhich reason the frame 17 (together with the unit consisting of thepusher, sliding plates and positioning conveyor etc.) is moved away fromthe stacking location 6.

The intermediate plate 8 serves to form not only the first tier of thestack S but also the entire stack S. The stack is only transferredcompletely to the waiting pallet P after it has been completed, whereinthe lateral walls 41 serve as a scraper.

In order to ensure that this works, the intermediate plate 8 or theparts 8A, B thereof is/are suspended in a height-adjustable manner froma lifting frame 40, so that it can be lowered in each case downwardsafter completion of one tier, so that the stack level is located at theheight of the positioning conveyor.

If the stack S is completed, the parts 8A, B of the intermediate plate 8are moved towards the side below the edge of the lateral walls 41 (inthe X-direction), wherein the packages or the stack remains in thestacking location 6 and comes to rest on the waiting pallet P aftercomplete removal of the intermediate plate 8.

The pallet P with the stack S loaded thereon is lowered further and (asabove) passes through a wrapping unit 19 to be wrapped in stretch filmfor stabilization (cf. FIGS. 21 and 22).

At the same time, the intermediate plate 8 has then been closed and anew stack-forming procedure can be commenced.

Subsequently, the pallet comprising the stack is transferred or unloadedby the fork-like carrier 42 of the lifting and lowering unit 10 onto aroller conveyor 9 to be transported away. The lifting and lowering unit10 corresponds substantially to the one previously described, but inthis case is a single-beam lifter.

Subsequently, a new empty pallet for the new stack is received and islifted to the waiting position below the intermediate plate.

FIGS. 16 to 19 show a schematic perspective view of the previouslydiscussed device for automatic layered stacking, wherein in this case atrolley R is arranged in the region of the stacking location 6 duringstacking.

The device 1 is suitable not only for loading pallets P but also forloading trolleys R.

For this purpose, the trolleys R are fed or transported away by the sameconveyor 9 as the pallets. For this purpose, the trolleys R are arrangedon carrier pallets 43 (cf. FIG. 17) which can be handled in the same wayas normal pallets.

The trolleys R are likewise moved by the lifting and lowering unit 10into the stacking location 6 from below.

In order to spread the sidewalls RS of the trolley R apart, a spreadingdevice 44 is provided which, during stacking, holds the sidewalls RS atleast perpendicularly or even bent open in a slightly inclined manneroutwards.

The sidewalls RS specifically have the characteristic of moving inwardlytowards one another.

Since the sidewalls RS of the trolley R correspond with the parts 8A, Bof the intermediate plate and the use thereof is therefore not possible,a separate and height-adjustable intermediate plate 45 arranged on theside of stacking location 6 remote from the positioning conveyor 2 isprovided for the stacking of trolleys R.

After the sidewalls RS have been spread, the intermediate plate isintroduced from this side in the manner of a carriage into the trolley Rin the Z-direction by means of a drive 51. For the purpose ofheight-adjustment, the intermediate plate 45 is suspended from a liftingframe 50 in a similar manner to the intermediate plate 8.

Subsequently, the stack S is formed, as previously, by placing thepackages W on the intermediate plate 45.

When the completely stacked stack is transferred to the trolley R byretracting the further intermediate plate 45, the rear sidewall 46(which in FIG. 17 has been omitted for improved clarity) serves ascraper. The rear sidewall 46 is also height-adjustable so as to “joinin” with the lifting or lowering of the intermediate plate 45, and ismovable in the direction of the positioning conveyor 2 or stackinglocation 6 (Z-direction), so that trolleys of different sizes can beused.

The rear sidewall 46 also serves as an attachment location for thespreading device 44.

The spreading device 44 consists of two pins 47 which are arranged atthe same height in the region of the expected sidewalls of the trolleyR, protrude from the sidewall forwardly into the trolley space and canbe displaced laterally outwards for spreading purposes. For thispurpose, the pins 47 are arranged in each case on a vertically orientedrotary disk 48 driven by a common drive 49 by means of a rotating cable.The drive is arranged on the rear wall of the rear sidewall 46 (cf.FIGS. 18 and 19).

As the trolley is introduced, the pins 47 are thus positioned on theinside. After the trolley has been introduced, the pins are displacedoutwards by a rotation of the rotary disks 48 and thus spread thesidewalls RS.

If the stacking procedure is completed, the pins 47 are then movedinwards and the intermediate plate 45 is retracted at the rear sidewall46 serving as a scraper, so that the stack S of the packages W comes tolie on the trolley R.

Subsequently, the stack is moved by means of the lifting and loweringunit 10 through the film-wrapping unit 19 and finally on the rollerconveyor 9 to be transported away.

The procedure can then start anew.

The invention claimed is:
 1. Device for automatically stacking packageson a support in a predetermined spatial arrangement to form a stack,comprising: at least one feeding conveyor which provides singulatedpackages in a predetermined sequence; a lifting and lowering unit forlifting and lowering a support, which is arranged in a stackinglocation, in the Y-direction; and a displacement device which adjoins anoutput end of the feeding conveyor and receives packages from thefeeding conveyor and transports the packages to predetermined positionsin the stack; wherein the displacement device comprises: a positioningconveyor which adjoins the output end of the feeding conveyor and isarranged horizontally and along a side of the stacking location, inorder to position the packages in the X-direction, at least one slidingplate and a pusher, in order to transport the packages from thepositioning conveyor in the Z-direction to the predetermined position inthe stack, wherein the positioning conveyor defines a travel path and isdesigned as a transfer cart and the transfer cart includes a transportsurface upon which packages are disposed to position the packages in theX-direction, and wherein the at least one sliding plate is designed as aflat, strip plate which is movable horizontally and along the side ofthe stacking location and transversely thereto, in order to receive thepackages from the positioning conveyor at the X-direction position whenthe packages are pushed by the pusher and to place the packages on thesupport or in the stack in the Z-direction, wherein a front of the atleast one sliding plate is initially disposed on a side of thepositioning conveyor opposite the stacking location, and wherein thefront of the at least one sliding plate is then extended across thetravel path of the positioning conveyor underneath the transport surfacewith a portion of the at least one sliding plate extending fromunderneath the transport surface beyond a perimeter of the transportsurface to receive packages from the transfer cart when the packages arepushed off the transport surface by the pusher and onto the portion ofthe at least one sliding plate extending beyond the perimeter of thetransport surface.
 2. Device as claimed in claim 1, wherein rails forthe transfer cart are arranged in the X-direction along the stackinglocation or the support, and wherein the transfer cart is configured totransport packages only in the X-direction.
 3. Device as claimed inclaim 2, wherein the transfer cart is designed having a C-shaped frame.4. Device as claimed in claim 2, wherein the transfer cart comprises astop on the side remote from the feeding conveyor in the X-direction. 5.Device as claimed in claim 4, wherein the stop is configured to bemovable away from the stop position.
 6. Device as claimed in claim 5,wherein the stop can be pivoted about an axis from the stop position toa release position.
 7. Device as claimed in claim 4, wherein the stopcomprises two stop wings which are pivotable in opposite directions. 8.Device as claimed in claim 1, wherein the positioning conveyor isfastened to the frame.
 9. Device as claimed in claim 8, wherein theframe is configured to be movable.
 10. Device as claimed in claim 1,wherein the transfer cart is designed having a C-shaped frame. 11.Device as claimed in claim 10, wherein the transfer cart comprises astop on the side remote from the feeding conveyor in the X-direction.12. Device as claimed in claim 11, wherein the stop can be pivoted aboutan axis from the stop position to a release position.
 13. Device asclaimed in claim 1, wherein the transfer cart comprises a stop on theside remote from the feeding conveyor in the X-direction.
 14. Device asclaimed in claim 13, wherein the stop is configured to be movable awayfrom the stop position.
 15. Device as claimed in claim 14, wherein thestop can be pivoted about an axis from the stop position to a releaseposition.
 16. Device as claimed in claim 14, wherein the stop comprisestwo stop wings which are pivotable in opposite directions.
 17. Device asclaimed in claim 15, wherein the stop comprises two stop wings which arepivotable in opposite directions.
 18. Device as claimed in claim 13,wherein the stop comprises two stop wings which are pivotable inopposite directions.
 19. Device as claimed in claim 13, wherein thepositioning conveyor is fastened to the frame.
 20. Device as claimed inclaim 8, wherein the frame is configured to be movable.
 21. Device asclaimed in claim 1, wherein the pusher is disposed above and not incontact with the sliding plate with the pusher configured to transportpackages from the transfer cart to the sliding plate.
 22. Device asclaimed in claim 1, wherein the transfer cart is configured to transportpackages only in the X-direction, and wherein the sliding plate isconfigured to extend in the Z-direction transversely across the path ofthe transfer cart.
 23. Device as claimed in claim 22, wherein the pusheris configured to extend over the transfer cart to push packages from thetransfer cart to the sliding plate.